For final World Trade tower, a construction obstacle course

Nearly 14 years after the Twin Towers were destroyed, there are clear signs the World Trade Center may once again be whole.

A tentative deal announced last month would have 21st Century Fox and News Corp. anchor the final building, known as 2 World Trade Center, providing a path forward for developer Larry Silverstein. Already, the companies have shown off new, cutting-edge designs for the skyscraper, thought up by Bjarke Ingels, one of the rising stars of the architecture world.

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But actually constructing Tower Two could prove to be one of the biggest challenges of the entire rebuilding effort, requiring extensive planning, a surgeon’s precision and the realization that there could be significant complications along the way. The problem faced by Silverstein and his new design team? Massive, hulking pieces of ventilation equipment take up much of the development site for 2 World Trade Center.

The system cannot be moved and must stay operational—it regulates the air quality in underground stairwells connected to the center’s transportation hub, which is opening in phases this year. The task of building around the equipment will not be a simple one, according to several prominent architects, including Ingels.

“I think you probably couldn’t find a more difficult place in the world to build a 1,300-foot tower,” Ingels said in a recent phone interview.

To keep the ventilation system online, Ingels’ team has been asked to figure out how to “weave” the building’s support columns through all the machinery. They must also work around emergency stairs that connect to the hub. On top of that, there also needs to be room for the “core” of the building, where all the elevators, electrical wiring and the tower’s own ventilation must go.

Construction crews will have to assemble the first three floors without disturbing the equipment. Then they must “duplicate” all of it; that is to say, they will build a replica of the machinery inside the tower. New air pipes will be snaked up the building. Then, somehow, the systems will be switched over without severely disrupting PATH train service or the underground retail shops.

“The machinery has to keep running to keep the hub alive,” Ingels said. “Duplicate the machinery, switch it on, and then we can start clearing the ground floor for our purposes. So, baked into the site is already a few additional challenges, above and beyond the programmatic and sort of gravity requirements.”

The 2 World Trade Center site is located next to the transportation hub and its grand “oculus.” The hub, designed by world-renowned architect Santiago Calatrava, has been a problem-plagued undertaking, delayed time and again as costs repeatedly grew, pushing the price tag to $3.9 billion. To the west is 1 World Trade Center, which shares a similar story and cost.

Tower Two already has a foundation, something that would certainly be advantageous if not for the fact it comes with all the ventilation equipment installed. Under a 2006 agreement between Silverstein and the Port Authority of New York and New Jersey, which controls the World Trade Center, the developer had to bring the project to street level to allow for the ventilation equipment to be placed on the surface. Silverstein has already built new a new tower at 4 World Trade Center and is currently constructing 3 World Trade Center.

Representatives for Silverstein, including World Trade Center Properties president Janno Lieber, have said they do not consider building around the equipment a significant obstacle.

“There isn’t going to be an issue,” Lieber told Capital last year in a previously unpublished interview. “Most of the mechanicals for the hub are in tower three. Most of the stuff that you see at grade at tower two is really to feed the below-grade retail. It’s not the hubs, per se.”

He was speaking prior to Ingels joining the project, and before News Corp. and Fox—both run by the Murdoch family—had entered formal negotiations. The original designer, famed British architect Norman Foster, was replaced at the request of the Murdochs. At the time, Lieber said he considered finding an anchor tenant to be the real challenge.

“I shouldn’t be flip,” he said. “It’s technically—it’s mechanics and so on, and it costs money. But that’s not going to be the issue that prevents timely construction of Tower Two.”

Indeed, several architects said they did not consider the task of moving the equipment to be impossible. Some allowed, though, that it would be “monumental.”

One prominent architect familiar with the site, who spoke on the condition of anonymity so as not to anger Silverstein, said he thought all the machinery and stairs are “seriously compromising their ability to build on top of it.” But, he conceded, the task is not impossible to complete—it will just take time, money and mental equity.

Others weren’t as foreboding. Craig Schwitter, principal at BuroHappold Engineering and an associate professor at Columbia University’s graduate architecture school, said he too thinks dealing with the equipment will come with an additional cost and challenges. But he noted that numerous buildings have been constructed over transit and faced similar difficulties. That would include tower two’s big brother, 1 World Trade Center.

“A lot of larger-scale building these days are built over transportation hubs,” Schwitter said. “Transportation and high rise and density go hand in hand. How often do you get to build a high rise in the middle of a green field?”

Ingels and his team, for their part, have already designed a tower that is complex enough on its own. It involves what Ingels said will appear to be seven separate, smaller buildings stacked on top of each other. On one side, facing the Sept. 11 memorial, the building would have a conservative façade, albeit one that tilts slightly, following the pitch of 1 World Trade Center. On the other side, tower two would feature large overhangs with outdoor gardens on several levels.

Ingels said the mechanical equipment counts among numerous obstacles, and says his firm continues to work on solutions.

“We’ve already spent six months of trying to solve a lot of added complications you get when you’re building in one of the densest cities, in one of the densest neighborhoods, in the world, on top of 11 separate public transportation lines and some central loading and power supply, etcetera,” he said. “So I think, we’ve definitely taken into account a lot of the things. Happily, we have a few more years before we have to be done, so there’s still a few things to iron out.”